A Brief History of the Marque
Rivista mensile del touring club ciclistico italiano, 1910
ROSSELLI. - L' ing. Rosselli fin dal 1899 ha presentato i suoi speciali motori Lilliput ed Optimus. Le motociclette Rosselli hanno 1 3/4 e 2 3 4 HP di "forza e come resistenza e velocità hanno dato finora buoni risultati.
Manufactured: Emanuel di A. Rosselli 1899-1910
Rosselli was based in Turin and known originally as Castellazzi & Rosselli. In 1899 they built the Lilliput with an engine mounted in front of the pedals and belt drive to the rear wheel.
In 1902 they also produced racing and touring motorcycles of 1 to 5 CV.
Lilliput motors "aplicablili a biciclette" were available separately, as were Optimus engines for boats, cars and vetturette.
In 1903 they manufactured 258cc versions with magneto ignition, belt drive and a larger fuel tank, and also offered a ladies or priests bike with a 1.75 hp engine, belt drive and a protective net to prevents the rider's skirts tangling in the mechanicals or spokes.
The company closed in 1910.
Sources: MC Storico Conti, archive.org et al